JP3038338B2 - Vertical firing furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical firing furnace for firing massive raw materials such as limestone and dolomite.

[0002]

2. Description of the Related Art In a conventional vertical firing furnace of this kind,
For example, a raw material passage having an annular cross section formed between the outer cylinder and the inner cylinder is filled with a raw material such as limestone to be subjected to firing to form a raw material packed layer, and the raw material passage is formed while lowering the raw material packed layer. A hot gas is caused to flow upward from below, and the raw material such as limestone is fired by the hot gas, and a part of the hot gas is passed through a hot gas outlet provided on the wall surface of the inner cylinder facing the raw material passage from the raw material packed bed. It has been practiced to take out the heat inside the inner cylinder outside of the raw material packed bed and to recover the exhaust heat, thereby improving the thermal efficiency as a firing furnace.

FIG. 4 illustrates the structure of a main part of a hot gas extracting section of a vertical firing furnace having a conventional structure as described above. In FIG. 4, 1 is an inner cylinder, 2 is a raw material passage, 3 is a hot gas outlet formed on the wall surface of the inner cylinder 1, 4 is a raw material such as limestone filled in the raw material passage 2, A is a raw material passage 2 B indicates the outside of the raw material packed layer, and B indicates the outside of the raw material packed layer.
Denotes a hot gas rising in the raw material packed layer A and flowing out from the hot gas outlet 3.

In such a configuration of the hot gas outlet 3, the hot gas G rises in the raw material packed bed A filled with the raw material 4 in the raw material passage 2 in the furnace, and the hot gas G And flows inside the inner cylinder 1 outside the raw material packed layer A as shown by the arrow in the figure. At this time, the hot gas flows into the inner cylinder 1 through the hot gas outlet 3 with the dust in the raw material accompanying the flow. The hot gas flowing into the inner cylinder 1 is taken out of the furnace and used for preheating combustion air.

[0005]

At the hot gas outlet 3, the material protrudes toward the lower surface 3a side of the hot gas outlet 3 as shown in the drawing by its repose angle RA to form a repose angle surface 3b. . Therefore, the hot gas is supplied to the repose angle surface 3b.
Through the inner cylinder 1. The amount of dust entrained in the hot gas is proportional to the flow velocity of the gas, but the maximum part of the gas flow velocity is the part of the raw material repose angle surface 3b, and B in the inner cylinder 1 outside the raw material packed bed A is flow velocity. Is the lowest part of For this reason, the amount of dust entrained by the hot gas in the portion that has passed through the material repose angle surface 3b has reached saturation or more, and the dust floats and settles in the gas flow, and as shown by D in the drawing, the dust And interfere with normal gas flow.

[0006] Such a phenomenon is also a problem in the case of a raw material which is normally fired, but it occurs remarkably when a raw material having a crystal composition with a high powdering rate is fired, and the gas flow is hindered. In addition, the operation of the kiln has become impossible, and the operation has been interrupted, forcing the removal of accumulated dust.

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned drawbacks of the prior art, and smoothly discharges dust accumulated at a hot gas outlet so that hot gas flows smoothly from the hot gas outlet. It is an object of the present invention to provide a vertical firing furnace capable of flowing out.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an outer cylinder and an upper and lower parts of the furnace.
Double with the inner cylinder suspended from the center of the outer cylinder
It has a cylindrical structure, and the space between the outer cylinder and the inner cylinder is a firing space.
Which will be a raw material passage annular cross-section of, while lowering the material packed layer increases the <br/> heat gas generated by the burner from below by countercurrent contact and fired raw material in the raw material passage with the hot gas to the surface in the material passage is formed on the wall surface of the inner cylinder
In a vertical firing furnace which is to be taken out of the raw material packed bed which is inside the inner cylinder from the raw material packed bed through a hot gas outlet located a predetermined distance above the hot gas generating burner ,
A bridge is provided in a raw material passage at an upper portion of the hot gas outlet,
The bridge itself has an internal space in the lower part of the bridge.
Form, the yellowtail below the bridge by the bridge
Following below the Tsu di inner space to form a source space portion constitutes a state in which two spaces of the bridge interior space and raw material space portion communicates with the heat gas outlet, originating in the burner
The generated hot gas passes through the raw material packed bed in the raw material passage from below.
To the raw material space below the bridge.
Discharge with the strike, and then
The structure was such that it could collide with the ceiling surface and flow to the hot gas outlet .

[0009]

[Function] An outer tube and an inner tube formed from the upper part to the lower part of the furnace.
Raw material passage as firing space of annular cross section between cylinders
Bridge with an internal space formed in the lower part of itself
Is attached. And, in the material passage,
Subsequent to the inner space of the bridge, a raw material repose angle portion is formed at the lower portion of the bridge by the action of the bridge to form a raw material space portion. A hot gas generation chamber formed on the inner cylinder wall
Hot gas outlet located at a predetermined distance above the over Nah 該Bu
It communicates with both spaces of the ridge inner space and the material space. The hot gas generated by the burner feeds the raw material in the raw material passage.
The packed bed is flowed upward from the bottom, and under the bridge
Since the raw material space is formed and discharged through the material repose angle surface, the dust floating along with the hot gas passes through the material repose angle surface and settles on the upper surface thereof. Deposits. The hot gas is supplied to the raw material space.
After being discharged into the bridge, it enters the interior space of the bridge and
The gas collides with the well surface and flows to the hot gas outlet. others
Therefore, part of the dust entrained by the hot gas
Stall due to collision and settle and accumulate on the material repose angle
Effectively reduces the amount of dust flowing to the hot gas outlet side
Will be reduced. And the bridge internal space is in the bridge itself
Because it is formed and communicates with the hot gas outlet itself,
Of hot gas flowing from the bed to the hot gas outlet (discharge)
Out) A passage is formed below the bridge by the bridge itself
In combination with the raw material space that
And a large volume to ensure that the hot gas
It is discharged to the hot gas outlet. The dust deposited on the repose angle of the raw material descends to the bottom of the furnace with the lowering of the raw material and is discharged out of the furnace. By the above, the hot gas is smoothly flow to the raw material packed layer outside the inner cylinder from the opening out hot gas stream, burning furnace is operated continuously.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view showing the entire structure of the vertical firing furnace of the present invention, and FIG. 2 is an enlarged longitudinal sectional view of a main part of a hot gas outlet of FIG. 1 and a sectional view taken along the line II-II in FIG. 3 is a sectional view taken along the line III-III in FIG. In these figures, the same parts as those in FIG.

In FIG. 1, the main body of the vertical firing furnace is an outer cylinder 6.
The inner cylinder 1 is suspended from the center of the furnace and supported by the top of the furnace to form a double cylindrical structure. The outer cylinder 6 and the inner cylinder 1 have an annular cross-section as a firing space. A raw material passage 2 is formed. The outer cylinder 6 is provided with a plurality of upper burners 8 and lower burners 9 each having a hot gas discharge port opened in the raw material passage 2 at equal intervals in the circumferential direction (in this embodiment, 5 burners).
Locations). A raw material such as limestone to be fired is introduced into the raw material passage 2 from a position indicated by an arrow 10 at the top of the furnace, and a raw material packed layer A is formed in the raw material passage 2 from top to bottom. The hot gas generated by the lower burner 9 is brought into countercurrent contact with the rising hot gas and fired.

A product outlet 11 is provided at the bottom of the furnace to take out quicklime as a fired product.
Reference numerals 12 and 13 denote connecting members which are provided in the same number as the burners 12 and 13 in the raw material passage 2 above the upper burner 8 and the lower burner 9, respectively, and connect the inner cylinder 1 and the outer cylinder 6.

A hot gas outlet 7 is provided on the wall surface of the inner cylinder 1 facing the raw material passage 2 above the connecting member 12 above the upper burner 8. The hot gas outlets 7 are provided at a plurality of locations (1 in the figure) at equal angular intervals in the circumferential direction.
However, the number of the upper burners 8 is the same as that of the upper burners 8, and the upper burners 8 are provided in the middle of the upper burners 8 adjacent to each other in plan view. . The raw material passage 2 at the upper portion of each of the hot gas outlets 7 is traversed across the raw material passage 2 and
Are mounted over the entire width of the bridge.

The hot gas flowing into the inner cylinder 1 from the hot gas outlet 7 is discharged out of the furnace from the upper portion thereof and introduced into the recuperator 14 where it is exchanged with the air supplied by the blower 15. The heated air is supplied to the upper burner 8 and the lower burner 9. Further, the hot gas provided for heat exchange in the recuperator 14 is guided by an exhaust fan 17 to a dust removing device 16 such as a cyclone, where the dust is collected and discharged to the atmosphere.

The hot gas outlet 7 will be described in more detail. The bridge 5 attached at the hot gas outlet 7 is formed as shown in detail in FIGS. That is, the bridge 5 is constructed of refractory bricks, has a predetermined width in the circumferential direction as shown in FIG. 3, and has a steep slope 5a corresponding to the hypotenuse of an isosceles triangle at the top with a sharp top. The vertical part 5 is connected to the steep slope 5a.
b is formed. As shown in FIG. 3, the lower part of the bridge 5 itself is hollowed to form sleeves 5c and 5c on both sides, and a space Sb is formed inside. As shown in FIG. 2, the lower end edge of the sleeve 5c is formed in an arc shape to improve the holding strength between the inner cylinder 1 and the outer cylinder 6 of the bridge 5 formed of refractory brick.

In FIG. 3, the raw material 4 flows down from the upper part of the bridge 5 along the steep slope 5a to prevent stagnation. Then, the raw material further flows down along the vertical surface 5b,
When it reaches the lower end of b, it forms the angle of repose 3b starting from there and descends. Therefore, a raw material space Sm is formed below the bridge 5 by the repose angle surfaces 3b, 3b on both sides. Therefore, the raw material space S is formed by this space Sm and the space Sb inside the bridge 5.

Further, as shown in FIG. 2, the action of the lower raw material passage inner cylinder 1 of 2 (outer cylinder 2) in the radial direction (the raw material passage in the width direction 2) the hot gas stream exit 7 of the bridge 5 Is formed, and the raw material space S is formed on the upper surface 3c so as to extend also in the width direction of the raw material passage 2. And
A hot gas outlet 7 is located in communication with the raw material space S in the width direction of the raw material passage 2. That is, as shown in FIG. 3, the width of the hot gas outlet 7 is
c, and the height thereof also corresponds to the height of the raw material space S. The bridge 5 is formed and attached so as to cover the hot gas outlet 7 in this manner.

In such a configuration, the hot gas which has risen through the raw material filling layer A of the raw material passage 2 reaches the hot gas outlet 7 and is formed by the raw material space S below the bridge 5 formed by the bridge 5. And flows into the hot gas outlet 7 to enter the inner cylinder 1 and flow to B outside the raw material packed bed A. Dust floating along with the hot gas settles at the portion passing through the raw material repose angle surfaces 3b, 3b and the inclined upper surface 3c and deposits on the upper surface of the raw material on the raw material repose angle surfaces 3b, 3b and the inclined upper surface 3c. It becomes dust D, reaches the furnace bottom with the descent of the raw material, and is discharged from the furnace through the product outlet 11.

When the hot gas flows out of the raw material space S to the hot gas outlet 7, the hot gas collides with the ceiling surface 5d of the space Sb inside the bridge 5 and then flows in the direction of the hot gas outlet 7. At this time, some of the dust entrained by the hot gas stalls and settles on the material repose angle surfaces 3b, 3b and the inclined upper surface 3c, so that the amount of dust flowing to the hot gas outlet 7 side is reduced. You. In addition, even if the dust extends from the upper surface of the raw material toward the hot gas inlet 7 and the dust is likely to accumulate, the raw material does not endure and descends, so that the hot gas inlet 7 is prevented from being blocked. In this way, there is no need to interrupt the operation of the firing furnace to remove the accumulated dust, thereby enabling efficient operation.

[0020]

[0021]

As is apparent from the above description, according to the present invention, in the raw material space below the bridge, dust entrained by the hot gas is deposited on the upper surface of the raw material, and the deposited dust is used by utilizing the flow of the raw material. and so is lowered together with the raw material from the hot gas outlet positions can be discharged from the furnace bottom to the outside of the furnace, the hot gas outlet is no and child or closed by depositing dust, the hot gas smoothly outside the furnace Can be drained to In this case, in the present invention, in particular, the hot gas
Of dust that is accompanied by
Stalls against the ceiling of the bridge interior space
The material is settled on the upper surface of the raw material,
The material under the bridge can be deposited
More sedimentation and accumulation of dust on the upper surface of raw material in space
Can be effectively performed, and the
The amount of strike can be effectively reduced. Also,
There is an internal space in the lower part of the
By being shaped below the bridge by the bridge
Along with the raw material space formed by the material
Make sure that the hot gas discharge passage to the
The volume can be secured and the hot gas flows out reliably.
Can be discharged into the mouth. Therefore, it is not necessary to stop the operation of the furnace as in the related art, and an excellent effect that efficient operation can be performed can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the entire structure of a vertical firing furnace according to an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part of a hot gas outlet of FIG. 1, and is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a longitudinal sectional view showing a main part of a hot gas outlet part of a vertical firing furnace having a conventional structure.

[Explanation of symbols]

 Reference Signs List 1 inner cylinder 2 raw material passage 3, 7 hot gas outlet 3b raw material repose angle 4 raw material 5 bridge 6 outer cylinder A raw material packed layer B outside raw material packed layer D accumulated dust S raw material space

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukiyoshi Tamoto 8-2, Goi-minamikaigan, Ichihara-shi, Chiba In-house Calceed Chiba Plant (56) References JP-A-61-40851 (JP, A) 58-69389 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F27B 1/08

Claims (1)

(57) [Claims] 1. An outer cylinder and an outer cylinder extending from an upper part to a lower part of the furnace.
A double circle with the inner cylinder suspended from the center of the cylinder
It has a cylindrical structure, and the space between the outer cylinder and the inner cylinder serves as a firing space.
It is the raw material passage annular cross-section, while lowering the material packed layer increases the hot gas generated by the burner from below by countercurrent contact with performing firing of the raw material in the raw material passage, the hot gas It is formed on the wall surface of the inner cylinder in surface to the material passage
Re vertical firing it was taken out into an interior of the inner cylinder <br/> material packed layer outside from the raw material packed layer through <br/> heat gas outlet located at a predetermined distance above the heat gas generation burner In the furnace, a bridge is provided in a raw material passage at an upper portion of the hot gas outlet, and a bridge internal space is provided at a lower portion of the bridge itself.
Is formed, and the bridge is provided under the bridge by the bridge.
Following below the bridge internal space to form a source space portion constitutes a state in which two spaces of the bridge interior space and raw material space portion communicates with the <br/> heat gas outlet, in the burner
The generated hot gas passes through the raw material packed bed in the raw material passage from below.
Flowed upward and into the raw material space below the bridge
Discharged with dust, then the bridge interior space
A vertical firing furnace characterized in that the vertical firing furnace has a structure capable of colliding with a ceiling surface of the furnace and flowing to the hot gas outlet .